Theoretical Studies on Transition Wavelengths and Transition Probabilities

A discussion is presented of some theoretical methods for predicting atomic transition wavelengths and transition probabilities that are especially useful for highly stripped ions. Particular attention is given to procedures involving model potentials and pseudo-potentials and to procedures involving expansions in inverse powers of the nuclear charge. The importance of relativistic effects is assessed. The results of some recent calculations are compared to experimental data. Theoretical studies of molecular absorption and emission are briefly summarized.

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SCREENING CONSTANT BY UNIT NUCLEAR CHARGE CALCULATIONS OF THE RYDBERG SERIES FROM METASTABLE STATE OF CALCIUM ION

International Journal of Advanced Research ◽

10.21474/ijar01/13121 ◽

2021 ◽

Vol 9 (07) ◽

pp. 227-236

Author(s):

Malick Sow ◽

◽

Papa Amadou L. Diagne ◽

Fatou Ndoye ◽

Momar T. Gning ◽

...

Keyword(s):

Experimental Data ◽

Metastable State ◽

Calcium Ion ◽

Nuclear Charge ◽

Theoretical Studies ◽

Accurate Data ◽

Rydberg Series ◽

Screening Constant ◽

Charge Calculations

We report in this paper energy positions of Rydberg series from metastable state of Ca3+ ion.. Calculations are performed up to n = 20 using the Screening Constant by Unit Nuclear Charge (SCUNC). The present results compared wellwith the experimental data of Ghassan A Alnaâ€™washi which are the only available values.The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies.

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ATOMIC TRANSITIONS IN q-DEFORMED FIELDS

Modern Physics Letters A ◽

10.1142/s0217732392003840 ◽

1992 ◽

Vol 07 (26) ◽

pp. 2407-2413 ◽

Cited By ~ 4

Author(s):

G. S. AGARWAL ◽

S. CHATURVEDI

Keyword(s):

Transition Probabilities ◽

Atomic Transition ◽

Absorption And Emission ◽

Atomic Transitions ◽

Atomic Medium

Unusual probabilities of absorption and emission of quons by an atomic medium are reported. The deviations from the usual atomic transition probabilities can be used as an evidence for quons if they were to exist and were to interact with matter.

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STUDIES OF PHOTOIONIZATION PROCESSES OF NITROGEN-LIKE O+ION USINGTHE SCREENING CONSTANT BY UNIT NUCLEAR CHARGEMETHOD

International Journal of Advanced Research ◽

10.21474/ijar01/13510 ◽

2021 ◽

Vol 9 (09) ◽

pp. 977-985

Author(s):

Babou Diop ◽

◽

Abdou Diouf ◽

Youssou Gning ◽

Maurice Faye ◽

...

Keyword(s):

Experimental Data ◽

Metastable State ◽

Effective Charge ◽

Nuclear Charge ◽

Theoretical Studies ◽

Rydberg Series ◽

Screening Constant ◽

Semi Empirical ◽

Experimental And Theoretical Studies ◽

Theoretical Results

In this present work, we have calculated the energies positions of the 2s22p2(1D)nd2P, 2s22p2(1D)nd2S, 2s22p2(1D)ns 2D, 2s22p2(1S)nd2D and 2s2p3(3P)np2D Rydberg series in the photoionization spectra from the 2PÂ° metastable state of the O+ ion. Calculations were performed up to n = 40 applyingthe Screening Constant by Unit Nuclear Charge (SCUNC) via its semi empirical formalism. The quantum defect and the effective charge are also calculated.The results agree within 98% to Aguilars experimental data, and with Sows theoretical results to within 99%. These data can be a useful guideline for future experimental and theoretical studies.

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Comparison of Sm II transition probabilities

Canadian Journal of Physics ◽

10.1139/p08-020 ◽

2008 ◽

Vol 86 (8) ◽

pp. 1033-1038 ◽

Cited By ~ 16

Author(s):

J E Lawler ◽

E A Hartog ◽

C Sneden ◽

J J Cowan

Keyword(s):

Rare Earth ◽

Ab Initio ◽

Transition Probabilities ◽

Chemical Elements ◽

Experimental Methods ◽

Research Note ◽

Atomic Transition ◽

Basic Data ◽

Theoretical Methods ◽

Rare Earth Spectra

This Research Note provides a comparison of experimental atomic transition probabilities in Sm~II from two recent publications. Basic data of this type for rare-earth spectra, including Sm~II, are very difficult to determine using ab-initio theoretical methods. Experimental programs are underway in several laboratories to determine these data for ongoing astrophysical studies of the origins of the chemical elements. The two recent and nearly simultaneous publications, which were based on very different experimental methods, provide transition probabilities in good, but not perfect, agreement.PACS Nos.: 32.70.Cs, 32.70.Fw, 32.30.Jc

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Polarimetric Observations of Red Variables: A Study of Gas and Particle Interactions

International Astronomical Union Colloquium ◽

10.1017/s0252921100073668 ◽

1979 ◽

Vol 46 ◽

pp. 386-408 ◽

Cited By ~ 2

Author(s):

G. V. Coyne ◽

I. S. McLean

Keyword(s):

Wavelength Dependence ◽

Stellar Atmosphere ◽

Molecular Absorption ◽

Absorption Bands ◽

Absorption And Emission ◽

Mira Variables ◽

Stellar Photosphere ◽

Regular Variable ◽

Red Supergiants ◽

Balmer Lines

AbstractIn recent years the wavelength, dependence of the polarization in a number of Mira variables, semi-regular variables and red supergiants has been measured with resolutions between 0.3 and 300 A over the range 3300 to 11000 A. Variations are seen across molecular absorption bands, especially TiO bands, and across atomic absorption and emission lines, especially the Balmer lines. In most cases one can ignore or it is possible to eliminate the effects due to interstellar polarization, so that one can study the polarization mechanisms operating in the stellar atmosphere and environment. The stars Omicron Ceti. (Mira), V CVn (semi-regular variable) and Mu Cephei (M2 la), in addition to other stars similar to them, will be discussed in some detail.Models to explain the observed polarization consider that the continuum flux is polarized either by electron, molecular and/or grain scattering or by temperature variations and/or geometrical asymmetries over the stellar photosphere. This polarized radiation is affected by atomic and molecular absorption and emission processes at various geometric depths in the stellar atmosphere and envelope. High resolution spectropolarimetry promises, therefore, to be a power-rul tool for studying stratification effects in these stars.

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EELS white line intensities calculated for the 3d and 4d metals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153919 ◽

1989 ◽

Vol 47 ◽

pp. 388-389

Author(s):

C. C. Ahn ◽

D. H. Pearson ◽

P. Rez ◽

B. Fultz

Keyword(s):

Experimental Data ◽

Line Intensity ◽

Transition Probabilities ◽

Initial Increase ◽

White Line ◽

Hartree Fock ◽

Line Intensities ◽

Integrated Intensity ◽

X Ray Absorption ◽

The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

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